4.1
INTRODUCTION
Risk is the chance of an event (viz., earthquake,
flood or industrial accident) happening that will
have negative impact on the society and environment.
Risk analysis deals with the systematic use of all
available information to determine: (a) how often
a specific hazard may occur and (b) the magnitude
of their probable consequences. It implies that
risk of a disaster is related to: (a) the hazard,
(b) the vulnerability of society, structures and
the environment to it, and (c) how well the hazards
and vulnerabilities are managed.
Risk analysis of an area involves the
following steps:
(i) Assess the hazard.
(ii) Vulnerability and Capability Assessment (VCA).
(iii) Quantify the risk.
(iv) Prioritise the actions.
Flood and Earthquake and are considered as the
two main natural hazards in Rohtak district Information
on the hazard scenario (chapter 3) in the district
is used here to calculate the risk.
4.2 RISK ANALYSIS OF ROHTAK DISTRICT
The steps for analyzing the risk posed
due to a hazard as mentioned above has been Adopted
sequentially for Rohtak
4.2.1 HAZARD ASSESSMENT:
Disaster results from the impact of a
hazard, therefore the first step of risk analysis
is to assess the hazard. Hazard assessment is
concerned with the properties of hazard itself.
1. IDENTIFICATION AND DESCRIPTION OF
HAZARD
(I) EARTHQUAKE
Rohtak district falls in Zone IV of Earthquake
Hazard Map (Map No.) of India.
(II) FLOOD
Flood is a regular phenomenon in Rohtak.
The most flood prone villages in the district
are situated. About 55 villages are vulnerable
to flooding due to the district’s particular
topography.
(B) QUALITATIVE HAZARD ANALYSIS:
4.2.2 VULNERABILITY AND CAPABILITY ASSESSMENT
(VCA)
(A) VULNERABILITY ASSESSMENT:
Vulnerability is defined as the degree
of loss to a given element at risk resulting from
a given level of hazard. Vulnerability analysis
(VA) is a process, which deals with the understanding
of the types and levels of exposure of persons,
property and the environment (against a hazard)
at a particular time. This section deals with
who and what are exposed to the earthquake. Hence
it is clear that information on certain key parameters
are essential in conducting VA. While assessing
vulnerability of Rohtak, information has been
taken from the 1991 census and emphasis has been
given on social, economic, housing and environment
issues.
(I) SOCIAL VULNERABILITY:
Social vulnerability mainly depends on
factors like population density, age, gender and
social caste. According to 1991 census, total
population in Rohtak was 776966 and population
for the year 2001 is 940036. It is seen from map
that position and settlement on loose soil make
the population of this tehsil more vulnerable
to damage due to soil liquefaction, which may
follow an earthquake. As the population along
this belt is above one lakh , a large number of
people are at risk. The district female population
is 692779 and it is 48.5 % of total population.
The sex ratio in Rohtak is 847 women per 1000
men. The age group also plays a major role in
identifying vulnerable groups. The census report
shows that age groups of 0 – 14, 15 –19,
50 –59 and more than 60 are more vulnerable
than other age groups. Male genders are more vulnerable
in 0 –14, 50 –59 and more than 60
age groups. Social caste is also important for
identifying the vulnerability of a particular
community.
(B) CAPABILITY ASSESSMENT:
Capability (or, manageability) is defined
as the degree to which a community can intervene
and manage a hazard in order to reduce its potential
impact. In indicates the resilience of the community
to hazards. Manageability of the community against
earthquake at Rohtak have been assessed from the
following steps which they take to combat the
bad impact of earthquake:
1. AWARENESS
It is observed that the awareness level
of the government body and general public is good.
The home guards and medical officer in the district
have conducted in awareness programmes.
(II) PREVENTION AND MITIGATION MEASURES:
Normally two types of measure viz., structural
and non-structural measures are followed. Two
conventional methods of mitigation adopted in
Rohtak for earthquake are timber framed buildings
and seismic huts. In seismic huts, people are
residing in masonry or adobe construction houses.
Under nonstructural measures, there are no standard
practices except some government level insurance
to all people in Rohtak
(III) PREPAREDNESS
The rescue and relief plan developed
in the guidance of district collector affirms
that the Government and the public have already
take preparedness measures.
(IV) RESPONSE CAPABILITY
Effort has been made by the district administration
to categorize the activities for response. Rescue
and relief teams have been constituted under the
leadership of an officer - in charge. Police control
system, medical relief responsibility and public
welfare issues are also explained in the existing
Rescue and Relief Action Plan of Rohtak Hence
there exists a well-coordinated response strategy
among the concerned departments and public.
(V) PUBLIC, GOVERNMENT AND NGO PARTICIPATION:
It has been observed that the teams constituted
to carry out rescue and relief operation have
representation from Govt., NGOs and public.
(VI) LAWS AND REGULATIONS:
There exists no hard and fast rules and regulations
for management of emergency due to natural disasters.
4.2.3 QUANTIFICATION OF RISK:
A simple quantitative method has been adopted
to assess the hazard, vulnerability and manageability
in Rohtak The methodology has been described as
follows:
1. Hazard Assessment of earthquake in Rohtak
has been done on the basis of information related
to its frequency of occurrence, intensity or severity
and its overall impact (Table No. IV). The factors
mentioned here for assessment have been categorised
as Certain, May occur and Not likely with numerical
value of 3,2 and 1, whereas Very, Moderate and
Low have been given numerical value of 3, 2 and
1 respectively. The risk due to the hazard calculated
from hazard assessment only over Rohtak (as is
shown in Table no.IV) is 5/3.
2. Vulnerability assessment in Rohtak against
earthquake has been done on the basis of the impact
of earthquake on human population, buildings,
infrastructures, resources and economy (Table
no V). The factors mentioned here for assessment
have been categorised as High, Medium and Low
with numerical value of 3, 2, 1 respectively.
(c) Manageability assessment for Rohtak has been
done by considering the factors viz., overall
awareness of the public and Govt., laws and regulation
governing this hazard, response capability of
Govt. and community, existing procedures of warning
or prediction system, prevention and mitigation
measures, involvement of NGOs (Table no. VI a
&VI b). Poor, Modest and Good with numerical
value of 1, 2, and 3 respectively have been considered
here to assess the manageability at Rohtak Hence
the risk at Rohtak because of earthquake hazard
only is calculated as:
4.2.4 PRIORITIZE THE ACTIONS:
With reference to the above mentioned risk analysis
methodology adopted for calculating the risk due
to an earthquake at Rohtak, it is recommended
that the activities to reduce losses should be
prioritized. Damages following an earthquake are
primarily due to collapse buildings and infrastructures,
hence among the activities taken to reduce losses,
strengthening of buildings and infrastructure
should be taken up a priority. The next priority
should be given to further increase the awareness
level of the Govt., NGOs and community and also
to sustain it.
1. VULNERABILITY
(i) Flood:
The drains have been designed with the formula
of 7 cusecs per sq. mile which can be attributed
to rainfall of "22 to 25" and the flood
waters can be cleared within six days except the
pockets/low lying areas of which water can not
be dewatered through gravity flow. So it is considered
that except these pockets, there will be no damage
to the crops in the in the area. It is pertinent
to mention that due to continuous flow, irrigation
through canals and tube wells, the water table
has come up and as a result thereof the crop pattern
in the area has also switched to rice mainly from
wheat, sugarcane, jawar and bajra. This has also
become an additional factor for rise in water
table. So the area is prone to floods. The main
dewatering process for inhabited area i.e., villages
and fields is being taken by the Irrigation Department.
III Preventive Measures:
i) Floods:
The floods can be anticipated, so stress
is to be laid for the preventive measures as per
saying "prevention is better than cure".
So far as Rohtak district is concerned, worse
affected has been the Rohtak town itself, because
its location is Bowl type i.e., flood watrer has
to be dewatered by providing three no. lifts form
the jeart of the city. The responsibility to cleat
the water rests with the Public Health Department
and to make the system more efficient, the various
steps such as round the clock electric supply
to the pumps by providing alternative feeders,
installation of stand by pumps. On the part of
Irrigation, the protection of First line and second
line ring bund which starts from Rohtak Gohana
Railway line up to the Drain No. 8 and then from
Hisar Road to Bhiwani Road and further up to Sunaria
Road should be well maintained, because as per
past history of floods of 1960, the Rohtak town
had been victim of Drain No. 8. Though, the drain
No. 8 has been rehabilitated and its capacity
has been considerably increased by deepening and
widening, but regular maintenance particularly
clearance of jungle which generally grown is the
bed of the drain also as this was the main factor
which led to the inundation of Rohtak town by
over flowing of drain No.8. Similarly, the worse
affected area was during1995, Meham and Sampla
due to non maintenance of drains in the area because
there was heavy wild growth of patera, kabli kikkar
etc. in the bed of pakasma drain due to which
there was flooding in Sampla town without heavy
rains in the catchment. Similarly, due to non-functioning
of link drains in Gohana sub-division i.e., Isapur
Kheri link drain, Bhambewa drain and Chhapra drain
which outall into the drain No. 8 could not function
properly and due to over flow at various points
there was unwanted sheet flow in Meham area and
worse affected villages were Madina, Mokhra, Behalba,
and Nindana. To counteract the floods in the said
area, Meham drain, Lakjanmajra drain have been
constructed with link drains which untimately
outfall into drain No. 8. The proper maintenance
of these drains will definitely prevent the floods
in the area. In additions to above, the various
preventive measures are discussed as under:
Design Criteria for Flood Works:
The drains have been designed with the formula
of 7 cusecs per sq. mile which can be attributed
to rainfall of "22 to 25" and the flood
waters can be cleared within six days except the
pockets/low lying area of which water can not
be dewatered through gravity flow. So it is considered
that except these pockets, there will be no damage
to the crops in the area. It is pertinent to mention
here that due to continuous flow irrigation through
canals and tune wells, the water table has come
up and as a result thereof the crop pattern in
the area has also switched to rice mainly from
wheat, sugarcane, jawar and bajra. This has also
become an additional factor for rise in water
table. So the area if prone to floods, the main
dewatering process for villages and fields is
being taken by the Irrigation Department, whereas
the dewatering process for villages and fields
is being taken by the Public Health Department.
The department has excavated number of drains
in the area considering the disaster caused by
floods of 1995.
Infrastructure of Drains:
To make the district flood-free, the rehabilitation
of the existing drains has been done under WRCP
while most of the drains have been constructed
under NABARD project. During 1995, there was sheet
flow between drain No.8 and JLN Feeder which ultimately
entered in Rohtak town particularly. To counteract
the same, Rohtak drain has been constructed which
outfalls into Kultana-Chhudani-Dhupania drain.
The latter has also been rehabilitated which outfalls
into Najafgarh drain and ultimately the water
is discharged kin river Yamuna. The list of the
existing drains in Rohtak district is attached
as Annexure-I.
3. Protection of Bunds.
The protection bunds are maintained by the Addl.
Deputy Commissioner through concerned BD&PO
every year. The detail of such bunds block-wise
is given in Annexure-II.
4. Dewatering Arrangements and Availability
of Material and Manpower.
(a) Irrigation Department:
The availability of pumping, machinery
and manpower in the Irrigation Department is as
under:
1. Permanent Pump Houses: During the flood season,
the primary responsibility of Irrigation Department
is to carry out the dewatering of the flood waters
affecting village abadies and fields. For this
purpose, 10 nos. permanent pump houses having
273 cusec capacity stand installed in order provide
relief to the village abadies, live-stock and
fields. The list of such pump houses is given
in Annexure-III.
2. Mobile Pumps: Besides, some area which is not
covered by these pump[ houses, mobile diesel pumping
sets having 270 cs. Capacity and electric pumping
sets having 630 cs. Capacity are also available
in Water Services Mechanical Division, Rohtak
for installation at various sites and ring bunds
to protect abadies and fields from fury of floods
as per site requirement. The list of the availability
of mobile pumps is also attached herewithas Annexure-Iv.
3. Temporary Electric Sites to be Installed up
to 30.6.
In addition to the above, some temporary electric
sites as per list attached as Annexure-IV stand
already identified as vulnerable sites where electric
pumping sets are installed before 30.6 every year
which will functioning as when necessity arises.
4. Deferred Electric Sites: Apart from this, there
are some more temporary sites, the installation
of which can deferred due to site being approachable
but electric connections are to be applied. These
sites are to be installed during floods, if required.
The list of such deferred sites is also enclosed
herewith as Annexure-VI.
In addition to this, some more temporary sites
are also installed in the fields according to
the intensity of rains and requirement in the
fields. So keeping in view the past experience,
about 115 nos. electric and 130 nos. diesel sites
will be installed in case of floods in the area.
The sites to be installed are also depicted on
the index plan attached herewith.
B-By Public Health Department:
For dewatering operation within Municipal
limit is the responsibility of Public Health Department
and for the said purpose, the following pumping
sets have been installed:
Main disposal -20 Cs.
Storm disposal -26 "
Harijan Basti -14 "
HUDA complex -60 "
Guru Nanakpura -10 "
Nehru Colony -12 "
Model Town -6 "
Thus a total of 148 Cs. capacity has been installed
by the Public Health Department for Rohtak town.
With urbanization of the town, the pondage area
has also been depleted and the entire quantity
of storm water has to be pumped out. The maximum
accumulation of storm water takes place in Chhotu
Ram Park area. It has a catchment area of 1200
acres and only 60 cusecs of pumping has been installed.
Thus in case of 4" of rainfall in a day 300
acre feet of water would be collected and it would
take 2 and half days to clear the water.
Pumping Machinery:
The following stand by pumps are also
available for dewatering of flood water.
1. Electric Motors Pumping Sets
1. 50 HP 9 Cs. 1No.
2. 35 HP 3.5 Cs. 1No.
3. 35 HP 2 Cs. 3No.
4. 10 HP 1Cs. 1No.
2. Diesel Engine Driven Pumping Sets
1. 100 HP 9 Cs. 1No.
2. 40 HP 5 Cs. 1No.
3. 35 HP 2 Cs. 2No.
4. 10 HP 1Cs. 3No.
(ii) Earthquake:
Earthquake is one of those natural disaster
where man, machine and science have failed to
forecast the occurrence and intensity of the earthquake.
Therefore, preventive measures for ensuring safety
of building, structures, communication facilities,
water supply lines, electricity and life are of
utmost priority.
The Gujrat earthquake has shown that the damage
could have been contained or reduced if people
had built earthquake resistant houses or taken
steps from time to time to strengthen the already
built structures. The soil of Rohtak town has
a very low load bearing capacity and hence does
not have high rise or multi-storeyed buildings.
The maximum height allowed both by the Municipal
Committee and HUDA is 36 feet or three storeyed
buildings. However, since it is an old township
there may be several houses, buildings and structures
which are about a hundred years old. Immediate
steps need be taken to get them vacated and then
demolished at an early stage. It is very important
to remember that Rohtak district is a very flood
prone district and Rohtak town has been badly
affected by flood waters several times, the worst
being those of 1962, 1983 and 1995 when the town
continued to be inundated for several days and
in some low lying areas for several weeks. These
stagnant waters must have definitely affected
the foundation and structure of both old and new
houses.
II. Similarly, the Ismaila Railway over-bridge
was badly affected by the flood waters of 1995
and the ROB was closed to heavy traffic for several
days. The PWD (B&R) authorities may be directed
to examine all such bridges and other like structures
on the National and State Highways and take measures
to strengthening them.
III. The Haryana Urban Development authority
has already issued orders making it mandatory
for all private builders, contractors and house
owners to get certificates from structural engineers
regarding the strength of their buildings and
al those going in for new constructions will also
have to get such certificates before shifting
to a newly constructed house.
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